Concerning elevator systems, a call-giving method is known wherein a passenger gives calls to an elevator system by means of a personal terminal device. This generally takes place already before going into the elevator car, e.g. in the elevator lobby. A terminal device can be a mobile phone or a means of communication comparable to it, by the aid of which a passenger can send a call wirelessly to the elevator system. When using a terminal devices, call-giving is generally based on so-called destination calls, in which case each passenger must be give with his/her terminal device a call to the floor to which he/she is traveling. On the basis of the call the elevator system allocates to the passenger an elevator car, using which he/she will get to his/her desired floor. The allocation takes place immediately in connection with the call-giving, after which the elevator system sends information about the allocated elevator car to the terminal device of the passenger. When the allocated elevator car arrives at the departure floor of the passenger (the call-giving floor), the doors of the elevator car open to let passengers into the elevator car. The open time (door time) is limited in such a way that the set maximum door time is not exceeded, so that the transport capacity of the elevator system can be maintained as optimal. There can also be sensors in connection with the elevator car and/or a door, from the signals of which sensors the elevator system can deduce whether passengers are coming/have come into the elevator car and/or are leaving/have left it. If, on the basis of the signals given by the sensors, no passengers are entering/leaving, the door of the elevator car can close and the elevator car can start moving.
When a passenger uses a personal terminal device for giving calls, the distance from the call-giving location to the elevators/elevator lobby can be very long indeed and the passenger does not have time within the scope of the aforementioned maximum door time to get into the elevator car serving him/her. In this case the doors of the elevator car close before the arrival in the elevator car of the passenger and the elevator car leaves the call-giving floor, serving other passengers that are already in the elevator car. To obtain elevator service, the passenger must therefore give his/her elevator call again, which of course hampers and delays the arrival of the passenger at his/her destination. On the other hand, the maximum door time cannot be unreasonably lengthened because passengers in the elevator car could experience uncertainty and confusion while waiting for the doors of the elevator car to close.